1. Field of the Invention
The invention relates to a gas turbine combustor.
2. Description of the Related Art
Conventional gas turbine utilizes a two-stage combustor which includes a pilot nozzle for forming a diffusion flame, as a pilot flame, along the axis of the combustor, and a plurality of main nozzles for discharging a fuel-air mixture to form premixed flames as the main combustion around the diffusion flame.
In the conventional gas turbine combustor, the premixed flames complete the combustion process in a short length in the axial direction of the combustor which may result in short flames or a rapid combustion adjacent a wall. When the combustion process is completed within a small volume, the volumetric density of the energy released by the combustion or the combustion intensity in the combustor becomes high so that a combustion-driven oscillation can easily be generated within a plane perpendicular to the axis or in the peripheral direction. The combustion-driven oscillation is self-excited oscillation generated by the conversion of a portion of the thermal energy to the oscillation energy. The larger the combustion intensity in a section of a combustor, the larger the exciting force of the combustion-driven oscillation to promote the generation of the combustion-driven oscillation.